Road building machine



April 10, 1934. E SCHUSTER 1,954,104

ROAD BUILDING MACHINE Filed Dec. 2, 1932 2 Sheets-Sheet 1 /N VE N 70R- fDU/YRD Smusrae- A ril 10, 1934. E. SCHUSTER ROAD BUILDING MACHINE Filed D90. 2, 1932 Sheets-Sheet 2 Mame g Patented Apr. 10, 1934 UNITED STATES ROAD BUILDING MACHINE Eduard Schuster, Milwaukee, Wis., assignor to Koehring Company, Milwaukee, Wis., a corporation Application December 2, 1932, Serial No. 645,476

. 3 Claims.

the levelled subgrade and between the lateral road forms is laid the concrete aggregate which is to form the road.

In the standard practice, before the concrete aggregate is laid onto the subgrade, the road forms are secured to the'ground by fastening by spikes; and at suitable intervals there are disposed transverse extending expansion joints to allow for expansion of the concreteof the finishecl road. When the aggregates are laid, it is common procedure to lay sufficient aggregates to form, when levelled, a layer of predetermined depth. Upon this layer is placed a reinforcing netting, and then further quantities of aggregates are laid and levelled to bring the road to the i finished thickness. 7

Another procedure now coming into vogue is the production of roads formed of so-called rolled concrete. In this form of road the concrete aggregates are laid to a depth exceeding the height I of the road forms. The aggregates are levelled, and then subjected to pressure by a heavy roller until the aggregates are compressed to a level of the road forms. When the aggregates set, this produces a very dense and hard roadway.

In either of these operations it is necessary, of course, to level the aggregates to the desired depth before the roadway is finished. It may be, in the usual type of road building operations, that it is desired to level off the aggregates at or belneath the level of the top of the road forms or, in the case of rolled concrete roads, the aggregates are levelled at a desired level, usually from about A to 1 above the level of the top of the road forms.

The present invention relates to an improved type of levelling machine which will perform the desired levelling operations at any depth below or above the top of the road forms without interfering with the operation of the machine. This cannot be done by the machines of the prior art, owing to the inability of the levelling blade to pass over obstructions in the road, such as the expansion joints, man-hole covers, and the like. In the present machine this passage is accomplished by simple mechanism which will quickly lift the blade over these expansion joints while allowing the blade to level the concrete up to these joints. Moreover, this same mechanism makes the present improved machine especially adapted for levelling the concrete deeply below the top of the road forms as well as substantially above the top of the forms where the rolled concrete type of road is being built.

In the present invention, means are also provided for securing the adjusting mechanism so that the levelling blade of the machine will be held at the adjusted point as the machine travels along the road. The adjustment of the machine is, therefore, very flexible and quickly operated.

The invention will be more readily understood by reference to the accompanying drawings, in which- Figure 1 shows a side elevation of the machine mounted to travel on the road forms and positioned for maximum depth of cut of the levelling blade.

Figure 2 is a top plan view of a part of the machine, showing the moimting on the road forms and the platform for the operator.

Figure 3 is a fragmentary front elevation of the machine, showing the levelling blade or screed with the machine mounted on the road forms, which are shown in section.

Figure 4 is a fragmentary view showing the lifting mechanism for the blade, the view being a section taken on the line 4-4 of Figure 2, and illustrates in dotted lines the movement of the lifting mechanism and the frame of the machine.

Figure 5 is a view in general somewhat like Figure 4, but showing the levelling blade in adjusted raised position to level the concrete aggregates at a level above that of the top of the road forms, the view showing the machine in position for use on rolled concrete.

Figure 6 is a view showing the adjusting device partly illustrated in Figures 1, 4, and 5. r

The machine is formed of a frame structure 1 being provided with a platform In for the oper ator, which platform is supported by the frame structure. The ends of the platform 1a rest upon the end beams of the frame.

The structure to be described hereinafter is understood to be substantially duplicated on each side of the machine, and accordingly the mechanism on one side only of the machine will be be described in detail.

Between the longitudinal beams l and lb are positioned the wheels or rollers upon which the machine is carried. The rear rollers 2 are provided with trunnions 2a which operate in bearings 2b.

The mounting of the front rollers 3 is different, as will be hereinafter explained, as it is through movement of the rollers 3 that the depth of cut of the levelling blade, or screed, is adjusted. The rollers 2 and 3 roll on the road forms 4, which are secured in position by spikes 5, in the usual manner.

Secured to the front beam of the machine, and extending across the front end thereof, is the levelling blade 7, secured in place by securing members 6. The blade '7 may be made of a plurality of sections, as illustrated, but this is not of importance to the invention.

The instrumentalities for adjusting the blade '7 will now be described, which adjusting is accomplished by suitably moving the front rollers 3.

To accomplish this action, there is provided a lever 8 having an actuating handle 9 and which is fulcrumed at 10. The lever carries the axle 11 upon which the wheel 3 is mounted. The lever 8 is also provided, adjacent its upper end, with a notch or recess 12, the purpose of which will be brought out in more detail hereinafter.

The lever 8 is in the form of a bracket, shown clearly at 13, which carries the fulcrum bearings 10a, which are rotatively mounted in the longitudinal beams 1 and 1b. The axle 11 extends between the sides of the bracket 13, between which sides the roller 3 is carried.

As before mentioned, there are provided in the road, expansion joints, illustrated at 1 1. When the blade 7 is operating beneath the top of the road forms, it is necessary to lift the blade over these expansion joints. This is accomplished by moving the handle 9 from the full line to the dotted line position in Figure 4, which movement tends todepress the rollers 3. This action being resisted by the road form upon which the rollers 3 operate, the front end of the frame will be lifted as shown in dotted lines in Figure 4, and the roller 3 takes the dotted line position. When the handle 9 is swung in the opposite direction, the frame and blade are again lowered to the former plane. Therefore, by operation of this lever back and forth. the levelling blade may be made to jump over the expansion joints, without interfering with the progress of the machine. It will be remembered that the lever 8 is duplicated on both sides of the machine except for the handle 9. The fulcrum bearings of each lever are secured to a shaft 15 which extends through the machine from side to side, and which is turned when the lever provided with handle 9 is actuated, thereby producing simultaneous actuation of the other lever, so that both sides of the frame of the machine will be lifted alike.

Since actuation of these levers 8 lifts the frame and the blade 7, this actuation is utilized, as will be obvious, to adjust the depth of cut of the blade 7. To maintain the blade in desired position of adjustment, it is necessary to hold the lever in such position. To accomplish this there is provided a U-shaped rod 16, carried in mountings 16a rotatively carried by the supports 17. The ends of the rod 16 are threaded, as indicated at 18, nuts 19 operating on these threads. This gives a simple means for adjusting the length of rod 16, by suitably positioning the nuts 19 on the threads 18, and sliding the rod through the mountings. Therefore, when the handle 9 is removed from the lever 8, the rod 16 may be positioned over the end of the lever 8 and brought into engagement with the recess 12. By tightening the nuts 19, the rod 16 is locked in its adjusted position; obviously, the longer the length of the rod 16, the lower will be the plane of the blade 7, and vice-versa; and accordingly, the blade 7 may be adjusted to level the aggregates in a plane above that of the top of the road forms 4, so that the machine is usable both in connection with the conventional type of road construction and also with the rolled concrete type of road. When not in use, the rod 16 is swung into inoperative position as indicated by the arrow in Fig. 5 and shown in Figs. 1, 2, and 4.

' The desired adjustments are therefore very simply made and retained, and the manipulations of the adjusting mechanism can be quickly made by the operator so as to prevent the blade from striking the expansion joints of the roadway.

The machine may be propelled by an internal combustion engine with the usual power transmitting instrumentalities for driving the rear rollers. Since this forms no part of the present invention, the driving mechanism is not shown; or the machine may be propelled in any other suitable manner; as for instance, by a traction vehicle coupled therewith.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is-

l. A road building machine of the character described, comprising, in combination, a frame, traction devices for carrying the frame, and adapted to run on usual road forms, a blade mounted on the frame for levelling road aggregates, lever mechanism for moving a pair of the traction devices for lifting the blade from a normal operating plane beneath the level of the top of the road form to a plane above the level of the top of the forms, and holding means for holding the lever at any desired position for securing the blade in corresponding adjustment, the means including a holding rod, supports and a mounting means for the rod rotatably carried by the supports, whereby the rod may be brought into and out ofv engagement with the lever, the effective length of the rod being adjustable to allow the lever to be secured by the rod at the desired position of adjustment.

2. A road building machine of the character described, comprising, in combination, a frame, traction devices for carrying the frame and adapted to run on usual road forms, a blade mounted on the frame, lever mechanism for moving a pair of traction devices for lifting the blade and the frame from a normal operating plane wherein the blade is disposed beneath the level of the top of the road form and shifted to a plane above the level of the top of the form, holding means for holding th lever at any desired position for securing the blade in corresponding adjustment, said means comprising a U-shaped rod, and means for attaching said rod to said frame.

3. A road building machine of the character described, comprising, in combination, a frame. traction devices for carrying the frame, and adapted to run on usual road forms, a blade mounted on the frame for levelling road aggregates, lever mechanism for moving a pair of the traction devices for lifting the blade from a normal operating plane beneath the level of the top of the road form to a plane above the level of the top of the forms, holding means for holding the lever at any desired position for securing the blade in corresponding adjustment, the means including a holding rod, supports and a mounting means for the rod rotatably carried by the supports, whereby the rod may be brought into and out of engagement with the lever, the effective length of the rod being adjustable to allow the lever to be secured by the rod at the desired position of adjustment, and a stop member formed as a part of said frame and limiting the movement of said lever mechanism in one direction.

EDUARD SCHUSTER. 

